Metal Injection Moulding of Nickel-Based Superalloy CM247LC

摘要

Metal Injection Moulding (MIM) is a promising new production technology for small to medium sizedparts with high geometric complexity as they are found in turbomachinery like aero engines orturbochargers. This study concerns the feasibility of manufacturing parts from nickel-based superalloyCM247LC via MIM and in particular the determination of optimum sintering and thermal processingparameters. CM247LC poses a serious challenge for MIM processing. Because of its high aluminumcontent, the strength potential is very high, but the sintering capability is severely restricted. Differentialscanning calorimetry (DSC) and dilatometry measurements as well as ThermoCalc simulations areused to optimize the sintering step of the MIM process route. Carbon, nitrogen and oxygen contents ofthe powder and the as sintered specimens are measured to evaluate the pick up of impurities duringprocessing. The microstructure of the as sintered specimens is characterized with respect to residualporosity, grain size and γ’ precipitation size and morphology. Room temperature strength andelongation in the MIM material are found to surpass conventional HIP material which is attributed tothe very fine grain size. Density and mechanical properties are observed to drop at the highestsintering temperatures. Ways to further improve the microstructure and strength will be discussed, inparticular for high temperature applications.